Premium
The Tensile Behaviour of an Injection‐Moulded Propylene–Ethylene Copolymer: the Effect of the Local Thermomechanical Processing Conditions
Author(s) -
Viana Júlio C.,
Cunha António M.,
Billon Noelle
Publication year - 1997
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/(sici)1097-0126(199706)43:2<159::aid-pi720>3.0.co;2-x
Subject(s) - materials science , composite material , ultimate tensile strength , copolymer , injection moulding , tangent modulus , composite number , modulus , melt flow index , polymer
In this paper the mechanical behaviour of a propylene–ethylene copolymer was characterised as a function of the local processing conditions using injection‐moulded axisymmetrical dumbbell‐like specimens of diameter 1·5mm. The moulding programme, designed according to the central composite face technique, included variation of the injection and mould temperatures and the flow rate. The local thermomechanical environment associated with each moulding condition was determined by filling simulations and quantified by the local bulk temperature and the maximum shear stress. Based on these parameters, thermal and thermomechanical indexes were defined to quantify the morphology of the mouldings, which was evaluated experimentally by the skin ratio. The tensile tests were carried out at two different constant velocities: 2 mm min ‐1 (0·56×10 ‐6 ms ‐1 ) and 3 ms ‐1 , in order to assess the tangent modulus, the strain and the energy at rupture. The results concerning processing–structure and processing–properties relationships are presented as 3D plots, based on polynomial interpolations of the experimental data. © 1997 SCI.